dev-manual, mega-manual, Makefile: Added support for new upgrade flow

Created a new figure for the devtool upgrade flow.  Put the figure
in the "figures" folder of the dev-manual and the mega-manual.
Updated the Makefile to include the new figure when creating
Tarball of the dev-manual and the mega-manual.

(From yocto-docs rev: 4b504f6f179ca7c7e9a69f23fc25b1f33ced8e44)

Signed-off-by: Scott Rifenbark <srifenbark@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

documentation/Makefile

@@ -135,6 +135,7 @@ TARFILES = dev-style.css dev-manual.html \
            figures/source-repos.png figures/yp-download.png \
            figures/recipe-workflow.png figures/build-workspace-directory.png \
            figures/devtool-add-flow.png figures/devtool-modify-flow.png \
+           figures/devtool-upgrade-flow.png \
            eclipse
 	endif
 
@@ -244,7 +245,7 @@ TARFILES = mega-manual.html mega-style.css figures/yocto-environment.png \
 	figures/build-workspace-directory.png figures/mega-title.png \
 	figures/toaster-title.png figures/hosted-service.png \
 	figures/simple-configuration.png figures/devtool-add-flow.png \
-	figures/devtool-modify-flow.png
+	figures/devtool-modify-flow.png figures/devtool-upgrade-flow.png
 	endif
 
 MANUALS = $(DOC)/$(DOC).html